Breaking the activity-stability trade-off remains a formidable challenge in the pursuit of nonprecious metal electrocatalysts for water splitting. Here, we report a programmable electrochemical assembly of wet-adhesive polydopamine (PDA) nanocages on Ni4Mo alloys to enhance the hydrogen evolution reaction (HER). We demonstrate that the catechol groups strongly coordinate with Ni/Mo active sites, reinforcing interfacial adhesion and suppressing metal dissolution under harsh electrochemical conditions. Benefiting from a porous rigid-flexible nanocage architecture, the Ni4Mo@PDA electrode operates stably for 3000 h at 500 mA cm-2 with a low HER overpotential of 125 mV in alkaline electrolyte and for over 500 h in anion exchange membrane water electrolyzers. First-principles calculations unravel the formation of a multisite catalytic network that reconfigures the interfacial energetics of HER intermediates through PDA-mediated Ni and Mo coordination. By leveraging biomimetic PDA nanocages, this study underscores the importance of interfacial buffering toward efficient and durable electrocatalysis on nonprecious alloys.
Kong et al. (Fri,) studied this question.